This multi-center, category D study has been completed. The study was designed to evaluate a new drug, ATC 97-01, designed to augment alpha-1 antitrypsin activity in patients with an inherited deficiency in this important plasma enzyme. The new drug was compared with an existing formulation (Prolastin). Patients were randomly allocated to the new drug or the comparator drug for ten weeks, after which all subjects received the new drug for a total study duration of two years. Over the last ten years, there have been significant improvements in the therapy of patients with inherited deficiencies of alpha-1 antitrypsin. It has been demonstrated that pasteurized, pooled human products can increase plasma levels of alpha-1 antitrypsin to biologically significant levels. In addition to this biochemical evidence, two large studies have suggested that the therapy has clinical efficacy. A European study demonstrated that augmentation therapy affected important parameters of lung function and, more recently, a study done in the United States demonstrated a survival advantage for patients receiving augmentation therapy for their inherited deficiency of alpha-1 antitrypsin. Because the supply of pasteurized, pool human enzyme has not been sufficient to meet patient demands, a new product was developed, and this study is testing that product. The new product, also made from pooled human plasma, is prepared using a solvent detergent treatment method, which greatly enhances viral safety over existing preparations.